Calculation of gravity and magnetic anomalies of finite-length right polygonal prisms

Abstract

Abstract An equation is derived for the vertical gravity field due to a homogenous body with polygonal cross-section and finite strike-length. The equation can be separated into the two-dimensional (2-D) terms of Talwani et al (1959) and exact terms for the contributions of the ends of the prism. Equations for the magnetic field due to a similar body were derived by Shuey and Pasquale (1973), who coined the term 'two-and-a-half dimensional' (2 1/2-D) to describe the geometry. Magnetic intensities are expressed as a vector sum, from which the common dot product formulation can be obtained by binomial expansion.